Wider is better

The K-Force Light platform is FSA's top component tier. The 386 EVO edition was designed for any of the bike frames designed around this new wider bottom bracket standard. For 2014, FSA has updated the graphics to reflect the winning heritage of the K-Force line.

Among the benefits of BB386 is the larger diameter, stiffer spindle. At 30mm, it's the same diameter as a BB30 spindle. The big difference between them is that the BB386 spindle is longer to allow its use in a bottom bracket shell width of 86mm. FSA uses a low speed extrusion to form the 7075 alloy spindle before they machine it to its final shape. It is co-molded into the 5-arm spider on the drive side arm. The composite spider is hollow to save precious extra grams, as are the crankarms. FSA molds a transverse rib into each hollow crankarm. It's an exacting process, but worth it since it increases the torsional rigidity. You'll appreciate the extra effort when you jump for the final sprint.

FSA employs T-30 Torx internal wrenching alloy fasteners for the chainring bolts. Though more difficult to produce, this type of hardware ensures that you can torque the fasteners properly without the worry of stripped bolts because of a sloppy interface with the tools. The K-Force Light Crankset has a 3K carbon weave finish on the hollow carbon fiber crankarms. The 7075 machined aluminum chainrings are ramped and pinned to ensure smooth shifting.

The K-Force Light 386 EVO Carbon Crankset comes in three sizes: 170mm, 172.5mm, and 175mm. Each length is available in Standard 53/39 or Compact 50/34 configurations. They have a Q-factor of 147mm, and are compatible with Shimano and SRAM 10 and 11-speed drivetrains.

Will this fit in my threaded bottom bracket?...

It looks likes it does not come with a BB since this standard can accommodate multiple BB types. You need to purchase the appropriate BSA threaded BB that is listed in that chart above (assuming it's Bsa and not Italian threading).